Light-absorbing Material Research Articles

Amplification of Dissymmetry for Circularly Polarized Photodetection by Cooperative Supramolecular Polymerization.

Circularly polarized photodetectors require chiral light absorption materials with high sensing efficiency and low costs. Here readily accessible point chirality has been introduced to dicyanostilbenes as the chiral source, facilitating remote chirality transfer to the π-aromatic core by cooperative supramolecular polymerization. The single-handed supramolecular polymers display powerful circularly polarized photodetection capability with a dissymmetry factor value as high as 0.83, superior to those of π-conjugated small molecules and oligomers. Strong chiral amplification occurs between the enantiopure sergeants and the achiral soldiers. The resulting supramolecular copolymers exhibit comparable photodetection efficiency to those of the homopolymeric ones, with a 90 % decrease in the enantiopure compound consumption. Therefore, cooperative supramolecular polymerization provides an effective yet economical avenue toward circularly polarized photodetection applications.

Amplification of Dissymmetry for Circularly Polarized Photodetection by Cooperative Supramolecular Polymerization

AbstractCircularly polarized photodetectors require chiral light absorption materials with high sensing efficiency and low costs. Here readily accessible point chirality has been introduced to dicyanostilbenes as the chiral source, facilitating remote chirality transfer to the π‐aromatic core by cooperative supramolecular polymerization. The single‐handed supramolecular polymers display powerful circularly polarized photodetection capability with a dissymmetry factor value as high as 0.83, superior to those of π‐conjugated small molecules and oligomers. Strong chiral amplification occurs between the enantiopure sergeants and the achiral soldiers. The resulting supramolecular copolymers exhibit comparable photodetection efficiency to those of the homopolymeric ones, with a 90 % decrease in the enantiopure compound consumption. Therefore, cooperative supramolecular polymerization provides an effective yet economical avenue toward circularly polarized photodetection applications.

The role of hydrophobic molecules in the optoelectronical attributes of triple-cation perovskite solar cells

The partial modification of perovskite cations has already been done to stabilize perovskite solar cells (PSCs). In this study, Cs/FA/MA triple-cation (3D) perovskite and PTA2PbI4 (2D)/3D perovskite were used as light-absorbing materials in PSCs. Phenyl trimethylammonium iodide (PTAI) was also used as a passivator. It was found that PTAI can serve as an original PTA two-dimensional (2D) cation and as a basis for the formation of 2D/3D heterostructure films. Since an improper post-annealing temperature leads to the uncontrollable degradation of 3D perovskites, this study examines post-annealing at various temperatures to make a 2D perovskite film on a 3D perovskite layer. The proper post-annealing temperature to make a 2D/3D structure was 150 °C exerted for five minutes. Through PTAI post-treatment in these optimum conditions, the morphology of the perovskite layer was improved, which confirms the facilitation of the charge transfer. Indeed, a 2D/3D heterostructure originating from a PTAI solution serves as a film to protect perovskite layer from destruction and improves charge transfer. Therefore, the treatment of perovskite layers, as practiced in this study, can enhances the stability and the efficiency of hole-transport-free PSCs and predispose their industrial production. The efficiency of the optimized device was enhanced for 35 % in comparison to the control samples. The device could also maintain 90 % of its PCE for 177 days.

A novel form-stable phase change material based on elastomeric copolymer and carbon nanotubes with photo-thermal conversion performance

In this paper, the composite form-stable phase change materials (FSPCMs) with a photo-thermal conversion function for solar thermal energy storage were prepared using paraffin wax (PW) as a PCM, both styrene ethylene butylene styrene (SEBS) and olefin block copolymer (OBC) as supporting materials, and carbon nanotubes (CNT) as an efficient light-absorbing material. The PW/SEBS + OBC composite with 80 wt% PW can maintain a stable shape without leakage above the phase change temperature. The latent heat of the PW/SEBS + OBC/CNT composite with 8 % CNT is 136.2 J/g, and the entrapment efficiency is 71.2 %. The prepared composite FSPCMs have good flexibility, thermal reliability, and thermal stability. And the absorbance of PW/SEBS + OBC/CNT composite is higher than that of pure PW and PW/SEBS + OBC. Moreover, the photo-thermal conversion efficiency of PW/SEBS + OBC/CNT composite with 2 wt% CNT, 4 wt% CNT, 6 wt% CNT, and 8 wt% CNT is 72.9 %, 81.9 %, 82.3 %, and 83.2 %, respectively. The prepared composite FSPCMs have a promising application in the field of solar energy storage.

Photovoltaic Performance of Perovskite Solar Cells and Their Continuous Charge Path Control in Electric Vehicles

Perovskite Solar Cells (PSCs) are new thin-film photovoltaic devices that have developed rapidly in recent years. It is considered a promising third-generation solar cell due to its high Monochromatic Incident Photon-to-electron Conversion Efficiency (IPCE), simple preparation process, and low cost. Firstly, the photoelectric characteristics of PSCs with four different structures and light-absorbing materials are analyzed. The results show that when CH3NH3PbI3 is used as the absorbing layer, the perovskite film with a porous structure has good crystallinity, and the photogenerated electron injection of TiO2 is more effective. The photoelectric Conversion Rate (CVR) of Pb-based organic cells with porous structure reaches 14.67%, and the photoelectric CVR of Pb-based organic cells with flat plate structure is only 6.35%. Then, a simple superimposed electrode type PSC is designed. Experiments have shown that the structure can greatly improve IPCE. The Spiro-MeOTAD layer should be retained. When the Layer one spraying amount is 250 μL, and the Layer two spraying amount is 500 μL, the IPCE obtained by the battery is the highest. The IPCE of the battery prepared by the ball milling method is higher than that of the battery prepared by the ultrasonic crushing method. Different substrate materials are compared. Using aluminum foil as the substrate can achieve the best photoelectric performance, and the corresponding photoelectric CVR reaches 11.62%. Based on the above test results, superimposed electrode-type PSCs are prepared and used in electric vehicle power generation devices. Super-Capacitor (SC) connection enables continuous charging in low-light conditions. The results show that the SC charges the designed superimposed electrode-type PSCs when the brightness decreases. The timing of charging and discharging is adjusted under the upper and lower limits of the threshold to ensure that the design PSCs remain charged.

Optimizing electromagnetic interference shielding ofcarbon nanofibersreinforced nylon 6, 6 nanocomposite films in terahertz range

AbstractThe widespread development and usage of electrical and electronic devices in THz frequency band has instigated great concerns regarding the anticipated functioning of devices. The world is in dire need to develop tunable shielding materials which are not only field functional but could also provide shielding against undesired electromagnetic signals by absorption as the primary mechanism. In this work, nylon 6,6 based hybrid nanocomposite films loaded with 0–50 wt% CNFs have been prepared on the cellulosic substrates by air spray coating technique. XRD and FESEM results have established formation of crystalline films having homogeneously distributed CNFs in the polymer matrix leading to formation of an efficient conductive network. IV measurements demonstrate a significant rise in the dc conductivity in the polymer nanocomposite samples with the gradual increase of CNF content in comparison to the pristine sample. Interestingly, sample containing 50 wt% CNFs has shown dc conductivity value of 0.03 Scm−1while shielding effectiveness (SE) of 44 dB obtained through THz‐TDS. The results hold a distinctive position in these samples which have outperformed at a very low thickness of ~570 μm as compared to the results obtained by many other novel polymer composites and present themselves a light weight field functional high THz absorption materials.

A three-dimensional antifungal wooden cone evaporator for highly efficient solar steam generation

Interfacial solar energy evaporation is an effective measure to alleviate the current global shortage of clean water resources. However, many solar evaporators are two-dimensional (2D) structured devices developed by coating light-absorbing materials on the surface of host materials, and the efficiency of solar steam generation is limited. For this reason, the present study reports a facile and environment-friendly method to construct a conical three-dimensional (3D) wooden evaporator, which uses flexible wood as the substrate and tannic acid complex as the light-absorbing material and is formed by further convolution. Reasonable structural design and material combination enable the evaporator to show excellent mildew resistance and highly efficient evaporation performance. The black decoration considerably improves the wood light absorption, resulting in high absorbance (>90%) of DW-TA-Fe3+ in the wavelength range of 200–800 nm. The water evaporation rate of the wooden cone evaporator can reach up to 1.79 kg m−2 h−1, about 1.6 times higher than that of the 2D evaporator. Moreover, the evaporator exhibits outstanding biological stability and effective desalination performance. This work is expected to offer a new direction in designing a 3D wooden evaporator for effective solar water desalination.

21.15%-Efficiency and Stable γ -CsPbI3 Perovskite Solar Cells Enabled by an Acyloin Ligand.

Cesium lead triiodide (CsPbI3 ) is a promising light-absorbing material for constructing perovskite solar cells (PSCs) owing to its favorable bandgap and thermal tolerance. However, the high density of defects in the CsPbI3 film not only act as recombination centers, but also facilitate ion migration, leading to lower PCE and inferior stability compared with the state-of-the-art organic-inorganic hybrid PSC counterpart. Theoretical analyses suggest that the effective suppression of defects in CsPbI3 film is helpful for improving the device performance. Herein, the stable and efficient γ -CsPbI3 PSCs are demonstrated by developing anacyloin ligand (1,2-di(thiophen-2-yl)ethane-1,2-dione (DED)) as aphase stabilizer and defect passivator. The experiment and calculation results confirm that carbonyl and thienyl in DED can synergistically interact with CsPbI3 by forming achelate to effectively passivate Pb-related defects and further suppress ion migration. Consequently, DED-treated CsPbI3 PSCs yield a champion PCE of 21.15%, which is one of the highest PCE among all the reported CsPbI3 PSCs to date. In addition, the unencapsulated DED-CsPbI3 PSC can retain 94.9% of itsinitial PCE when stored under ambient conditions for 1000h and 92.8% of its initial PCE under constant illumination for 250h.

Oxygen-deficient low band gap black zirconia nanoparticle synthesis and tailoring its band gap/photoluminescence via silver doping

This study focuses on the non-aqueous sol-gel synthesis of zirconia nanopowder and explores the tunability of its band gap, absorption, and photoluminescence. Multiple characterization techniques were used to examine the impact of oxygen vacancies (color centers) and silver doping on changes in the structural and optical properties of zirconia. XRD results confirmed the rare black-colored pure tetragonal zirconia and monoclinic-tetragonal mixed zirconia products. The UV–Vis analysis provided insights about the absorbance and confirmed the extraordinarily high absorbance over the entire visible spectrum of electromagnetic radiation and also ascertained the defect level that governed the low band gap of the synthesized black zirconia powders. With increasing the doping concentration, the photoluminescence emission spectroscopy stimulated at an excitation wavelength of 250 nm revealed a rising luminescence peak at 422 nm (2.94eV). The distinctive stretching modes of zirconia powder samples were validated by FTIR investigations. The FESEM was used to study the microstructure's morphology, and the EDX spectrum was used to analyze the samples' elemental composition. The high-bandgap white samples with strong PL emission (blue) can be used to create high-quality wLEDs, whereas the low-bandgap black zirconia may prove to be an outstanding solar light absorption material.

Highly photosensitive CsPbBr[formula omitted] NCs-graphene phototransistor with memory function

A high-performance Violet-light phototransistor with memory function was fabricated using CsPbBr3 nanocrystals as light absorption material, graphene as fast charge transfer channel, and graphene oxide as charge storage medium. The device demonstrated a responsivity of 2 × 103 A/W and a detectivity of 2.3 × 1012 Jones under illumination of a 405 nm laser. Moreover, the phototransistor showed an excellent photoswitching stability and a high response speed with the rise/decay times of 93/31 ms, respectively. The photoresponse mechanism was discussed using a charge injection model in an energy band diagram of CsPbBr 3 NCs and graphene interface. In addition, the device exhibited charge storage capabilities with a memory window of about 0.4 V attributed to graphene oxide as trapping layer. This work provides a viable route to fabricate phototransistors with storage capabilities.

Lead-free organic–inorganic azetidinium alternating metal cation bromide: [(CH2)3NH2]2AgBiBr6, a perovskite-related absorber

A new metal bromide perovskite derivative, azetidinium silver bismuth bromide is synthesized as a light-absorbing material.

Joint growth of BiOI and BiSI films in the chemical deposition process

Films of bismuth oxoiodide and thioiodide BiOI and BiSI as a light absorber for solar cells were synthesized and characterized. The influence of the duration of the chemical deposition process on the composition and morphology of the obtained films has been studied. It has been shown that BiOI is formed at a short deposition time, while BiOI and BiSI joint growth with an increase in the deposition time. The synthesized BiOI/BiSI photoelectrodes demonstrate a developed morphology, the invariance of the surface microstructure during stationary polarization measurements, as well as a heightened photocorrosion resistance. The high stability of operation in a photoelectrochemical cell reveals the potential of the new BiOI/BiSI light-absorbing material as a promising semiconductor for solar cells, photoelectrochemical sensors, detector and photocatalysts.

Intrinsic defects at the interface of the FAPbI3/MAPbI3 superlattice: insight from first-principles calculations.

The use of a superlattice structure is an effective strategy to develop novel perovskites and obtain excellent light-absorbing materials. Based on first-principles calculations, we systematically studied the properties of intrinsic point defects at the interface of the FAPbI3/MAPbI3 superlattice. Our calculations show that charged defects are easier to form as compared to neutral ones at the superlattice interface due to low formation energies. Most defects with low formation energies have a shallow level in the band gap, and some deep level defects have high formation energies, so the superlattice perovskite exhibits high defect tolerance. PbI3+ is a dominant and detrimental defect, which acts as a non-radiative recombination center because it has low formation energy and a deep transition level. To avoid the generation of PbI3+ defects, it is suggested to synthesize FAPbI3/MAPbI3 superlattices under I-rich conditions. The calculated light absorption coefficients and photovoltaic performance parameters demonstrate that the presence of defects leads to a certain degree of reduction in light absorption and power conversion efficiency (PCE) of solar cells made of FAPbI3/MAPbI3 superlattices, but the excellent performance of the perovskite solar cell (PSC) is basically retained. The superlattice perovskites are still promising candidates for light-absorbing materials of PSCs. This study is expected to contribute to a better understanding of the properties of defects at the superlattice interface and provide theoretical support for the design of high performance PSCs.

Enhanced photochemical activity and ultrafast photocarrier dynamics in sustainable synthetic melanin nanoparticle-based donor-acceptor inkjet-printed molecular junctions.

Melanin is a stable, widely light-absorbing, photoactive, and biocompatible material viable for energy conversion, photocatalysis, and bioelectronic applications. To achieve multifunctional nanostructures, we synthesized melanin nanoparticles of uniform size and controlled chemical composition (dopamelanin and eumelanin) and used them with titanium dioxide to fabricate donor-acceptor bilayers. Their size enhances the surface-to-volume ratio important for any surface-mediated functionality, such as photocatalysis, sensing, and drug loading and release, while controlling their chemical composition enables to control the film's functionality and reproducibility. Inkjet printing uniquely allowed us to control the deposited amount of materials with minimum ink waste suitable for reproducible materials deposition. We studied the photochemical characteristics of the donor-acceptor melanin-TiO2 nanostructured films via photocatalytic degradation of methylene blue dye under selective UV-NIR and Vis-NIR irradiation conditions. Under both irradiation conditions, they exhibited photocatalytic characteristics superior to pure melanin and, under UV-NIR irradiation, superior to TiO2 alone; TiO2 is photoactive only under UV irradiation. The enhanced photocatalytic characteristics of the melanin-TiO2 nanostructured bilayer films, particularly when excited by visible light, point to charge separation at the melanin-TiO2 interface as a possible mechanism. We performed ultrafast laser spectroscopy to investigate the photochemical characteristics of pure melanin and the melanin-TiO2 constructs and found that their time-resolved photoexcited spectral patterns differ. We performed singular value decomposition analysis to quantitatively deconvolute and compare the dynamics of photochemical processes for melanin and melanin-TiO2 heterostructures. This observation supports electronic interactions, namely, interfacial charge separation at the melanin and TiO2 interface. The excited-state relaxation in melanin-TiO2 increases markedly from 5 ps to 400 ps. The results are remarkable for the future intriguing application of melanin-based constructs for bioelectronics and energy conversion.

Calculation of excited states of monolayer TPPA-COF based on first principles.

Two-dimensional covalent organic frameworks (COFs) have always been a hot topic in condensed matter physics. Herein, the first 100 excited states of the TPPA-COF are calculated to investigate the optical absorption properties of the materials in the interval. The stable molecular structure of monolayer TPPA-COF is obtained by first-principles calculation, which can be regarded as a hexagon with an aperture size of 18.25 Å. By means of the band structure and density of state analysis, it is found that the monolayer band gap width of the TPPA-COF is 1.52 eV. All excited states of the TPPA-COF exhibit obvious pi → pi* (delocalized π to anti π) local excitation characteristics through analysing the spatial distribution of the electron-hole pairs of the 10 excited states with the highest oscillator strength among the first 100 excited states. In addition, the simulated UV-vis spectra show that the maximum absorption intensity of the TPPA-COF is about 357 684 mol-1 cm-1, indicating that the TPPA-COF is a potential light-absorbing material.

Molecular investigation of the multi-phase photochemistry of Fe(III)-citrate in aqueous solution.

Iron (Fe) is ubiquitous in nature and found as FeII or FeIII in minerals or as dissolved ions Fe2+ or Fe3+ in aqueous systems. The interactions of soluble Fe have important implications for fresh water and marine biogeochemical cycles, which have impacts on global terrestrial and atmospheric environments. Upon dissolution of FeIII into natural aquatic systems, organic carboxylic acids efficiently chelate FeIII to form [FeIII-carboxylate]2+ complexes that undergo a wide range of photochemistry-induced radical reactions. The chemical composition and photochemical transformations of these mixtures are largely unknown, making it challenging to estimate their environmental impact. To investigate the photochemical process of FeIII-carboxylates at the molecular level, we conduct a comprehensive experimental study employing UV-visible spectroscopy, liquid chromatography coupled to photodiode array and high-resolution mass spectrometry detection, and oil immersion flow microscopy. In this study, aqueous solutions of FeIII-citrate were photolyzed under 365 nm light in an experimental setup with an apparent quantum yield of (φ) ∼0.02, followed by chemical analyses of reacted mixtures withdrawn at increment time intervals of the experiment. The apparent photochemical reaction kinetics of Fe3+-citrates (aq) were expressed as two generalized consecutive reactions of with the experimental rate constants of j1 ∼ 0.12 min-1 and j2 ∼ 0.05 min-1, respectively. Molecular characterization results indicate that R and I consist of both water-soluble organic and Fe-organic species, while P compounds are a mixture of water-soluble and colloidal materials. The latter were identified as Fe-carbonaceous colloids formed at long photolysis times. The carbonaceous content of these colloids was identified as unsaturated organic species with low oxygen content and carbon with a reduced oxidation state, indicative of their plausible radical recombination mechanism under oxygen-deprived conditions typical for the extensively photolyzed mixtures. Based on the molecular characterization results, we discuss the comprehensive reaction mechanism of FeIII-citrate photochemistry and report on the formation of previously unexplored colloidal reaction products, which may contribute to atmospheric and terrestrial light-absorbing materials in aquatic environments.

Tailoring of CsPbIBr<sub>2</sub> perovskite crystallization via phenylthiourea for stable and efficiency perovskite solar cells

Inorganic CsPbIBr<sub>2</sub> perovskite has been considered as a promising light-absorbing material for solar cells due to its high stability and suitable bandgap. Although the remarkable improvement of CsPbIBr<sub>2</sub> PSC has been achieved, the efficiency of this cell is still lower than those of other analogues and far below its theoretical limit. This is mainly due to the serious charge recombination in the as-fabricated CsPbIBr<sub>2</sub> cells derived from the poor-quality CsPbIBr<sub>2</sub> perovskite film with a large quantity of defects and numerous grain boundaries. Therefore, fabricating high-quality CsPbIBr<sub>2</sub> perovskite film is a key factor for the further efficiency improvement of CsPbIBr<sub>2</sub> PSCs. Herein, phenylthiourea (PTU) additive is introduced into the CsPbIBr<sub>2</sub> precursor to tailor the crystallization of CsPbIBr<sub>2</sub> perovskite for fabricating high-quality CsPbIBr<sub>2</sub> perovskite. The C=S group of PTU can coordinate with PbBr<sub>2</sub> in the precursor owing to the lone-pair electrons on S and the empty orbits of Pb<sup>2+</sup>. The strong interaction between PTU and the CsPbIBr<sub>2</sub> precursor components can form PTU·Pb···Br(I) intermediate phase in the precursor upon PTU introduction. The PTU·Pb···Br(I) intermediate phase can reduce the nucleation rate of perovskite and modulate the perovskite crystal growth because the extra energy is required to break the strong coordination bond in the intermediate phase, resulting in a low crystallization rate of CsPbIBr<sub>2</sub> perovskite. Such a retardation of perovskite crystallization is conducive to the formation of high-crystallinity perovskite film with smooth surface, large crystal grains, high crystallization, and low density of defect. Meanwhile, the decomposition of PTU during thermal annealing makes the S<sup>2–</sup> inserted into interstitial of CsPbIBr<sub>2</sub> crystal lattice, which greatly enhance the stability of CsPbIBr<sub>2</sub> perovskite. The carbon-based PSCs with a normal n-i-p structure of FTO/compact-TiO<sub>2</sub> layer/meso-TiO<sub>2</sub> layer/perovskite film/carbon layer are fabricated, and their photovoltaic performances are measured under a simulated AM1.5 illumination (100 mW·cm<sup>–2</sup>). The PSC based on PTU-CsPbIBr<sub>2</sub> perovskite delivers a high power conversion efficiency of 10.09%, which is much higher than that of the control device. This great improvement of photovoltaic performance can be attributed to the largely promoted perovskite quality, which enhances the charge collection and suppresses the charge recombination in the device. In addition, the unencapsulated device preserves 82% of the initial efficiency after being stored under ambient condition for 35 days, suggesting excellent stability. Therefore, this work provides an effective complementary strategy for effectively improving the performance of inorganic PSCs.

Ternary diagrams of phase, stability, and optical properties of cesium lead mixed-halide perovskites

Cesium lead halides have been intensively studied as promising light absorption and emission materials. However, the complexity and instability of their phases has prevented a comprehensive investigation of the structural and optical properties of Cs-based mixed halides over a broad range of mixing ratios. Herein, we derive the ternary diagrams of phase, optical bandgap, and photoluminescence intensity of cesium lead halide perovskites (CsPbX3), with three vertices of CsPbI3, CsPbBr3 and CsPbCl3. For material property tests, mixed halide perovskite powders are synthesized using a facile solid-state reaction method. The orthorhombic perovskite (γ) phase, which is desired for photovoltaic and optoelectronic applications, is successfully obtained by quenching the powders from 350 °C to room temperature. By comparing the phase diagrams of as-ball-milled and heat-treated powders, we report a single-phase region (γ-phase) and a multi-phase region (I-rich and Cl-rich γ-phases). In aged powders having single-phase compositions, Cl-rich compositions presented considerably higher phase stability than I-rich ones. In the single-phase region, the lattice constant increases and optical bandgap decreases almost linearly with increase in average size of X-site ions, as per Vegard's law with extremely small bowing parameters (< 0.1 Å). Therefore, one can easily design an infinite number of composition combinations in the single-phase boundary to achieve a desired bandgap in the range of 1.73–2.96 eV. Ternary maps of photoluminescence intensity demonstrate potential compositions for high-performance optoelectronics. Our results provide a valuable database for developing desirable perovskite compositions for various optoelectronic applications.

Research on Anti-Icing Performance of Graphene Photothermal Superhydrophobic Surface for Wind Turbine Blades

In this study, graphene is used as a photothermal material, which is added to the SiO2 superhydrophobic solution treated with fluorine silane, and then sprayed on the copper plate surface to prepare a new type of photothermal superhydrophobic surface with contact angles up to 160.5° and 159.8°. Under the conditions of natural convection, the effects of photothermal superhydrophobic surfaces on droplet condensation, freezing, and frost growth are investigated in different environments. The results show that the photothermal superhydrophobic surface can not only delay the freezing of surface droplets, prolong the freezing time of droplets, and reduce the thickness of the frost layer, but also allow for the rapid removal of droplets under near-infrared (NIR) irradiation. If the droplet is irradiated by an infrared laser emitter while the cooling system is still turned on, the internal temperature of the droplet will always be higher than the crystallization temperature under the illumination intensity of 2 W/cm2, and the droplets will not freeze. With the extension of irradiation time, the droplet will evaporate, and the volume of the droplet will decrease. On the basis of summarizing and evaluating the study on the anti-icing performance of superhydrophobic surfaces and the properties of photothermal materials, a new research direction regarding the anti-icing of fan blade surfaces was established. This kind of surface combines the photothermal capabilities of light absorption materials with the micro- and nanostructure of the superhydrophobic surface to improve the anti-icing capability of wind turbine blade surfaces in difficult conditions.

Trans‐spatial Structure Additive Passivated Sn(II) for High‐efficiency CsSnI3 Perovskite Solar Cells Fabricated in Humid Air

AbstractBlack crystalline γ‐CsSnI3 is an ideal light absorption material to replace lead‐based perovskite due to its low biotoxicity and excellent photoelectric properties. However, CsSnI3 is usually prepared in a low humidity inert atmosphere because of its oxidation in air. The severe preparation environment, on the other hand, will surely raise the economic cost of mass production. Therefore, a kind of additive engineering is proposed to introduce (1R, 2R)‐(−)‐1,2‐diaminocyclohexane (transDACH), a small nitrogen‐containing ligand with trans‐spatial structure, into the perovskite layer, which can stabilize Sn2+ in the preparation process, allowing for the preparation of efficient and stable perovskite solar cells under high humidity conditions. The forward scan maximum power conversion efficiency (PCE) of the CsSnI3‐transDACH device reaches 5.49%, the highest for hole‐free carbon‐based CsSnI3 PSCs prepared in humid air conditions. Furthermore, the transDACH‐modified devices retain 73.7% of their original PCEs after 160 hours of storage in ambient air conditions.